Adjuvant Pembrolizumab versus Observation in Muscle-Invasive Urothelial Carcinoma

BACKGROUND: Muscle-invasive urothelial carcinoma is an aggressive disease with high rates of relapse. Whether pembrolizumab as adjuvant therapy would be effective in patients with high-risk muscle-invasive urothelial carcinoma after radical surgery is unknown.

METHODS: In this phase 3 trial, we randomly assigned patients, in a 1:1 ratio, to receive pembrolizumab at a dose of 200 mg every 3 weeks for 1 year or to undergo observation. Randomization was stratified according to the pathological stage, centrally tested programmed death ligand 1 (PD-L1) status, and previous neoadjuvant chemotherapy. The coprimary end points were disease-free survival and overall survival in the intention-to-treat population. We considered the trial to be successful if either disease-free survival or overall survival was significantly longer with pembrolizumab than with observation.

RESULTS: A total of 702 patients underwent randomization; 354 were assigned to receive
pembrolizumab, and 348 were assigned to observation. As of July 5, 2024, the median duration of follow-up for disease-free survival was 44.8 months. The median disease-free survival was 29.6 months (95% confidence interval [CI], 20.0 to 40.7) with pembrolizumab and 14.2 months (95% CI, 11.0 to 20.2) with observation (hazard ratio for disease progression or death, 0.73; 95% CI, 0.59 to 0.90; two-sided P=0.003). Grade 3 or higher adverse events (regardless of attribution) occurred in 50.7% of the patients in the pembrolizumab group and in 31.6% of the patients in the observation group.

CONCLUSIONS: Among patients with high-risk muscle-invasive urothelial carcinoma after radical surgery, disease-free survival was significantly longer with adjuvant pembrolizumab than with observation. (Funded by the National Cancer Institute of the National Institutes of Health and others; Alliance A031501 AMBASSADOR ClinicalTrials.gov number, NCT03244384.)

Authors: A.B. Apolo, K.V. Ballman, G. Sonpavde, S. Berg, W.Y. Kim, R. Parikh, M.Y. Teo, R.F. Sweis, D.M. Geynisman, P. Grivas, G. Chatta, Z.R. Reichert, J.W. Kim, M.A. Bilen, B. McGregor, P. Singh, A. Tripathi, S. Cole, N. Simon, S. Niglio, L. Ley, L. Cordes, S. Srinivas, J. Huang, M. Odegaard, C. Watt, D. Petrylak, J. Hoffman‐Censits, Y. Wen, O. Hahn, C. Mitchell, A. Tan, H. Streicher, E. Sharon, H. Moon, M. Woods, S. Halabi, G. Perez Burbano, M.J. Morris, and J.E. Rosenberg

Affiliations: From the Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda (A.B.A., N.S., S.N., L.L., L.C.), the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore (J.H.-C.), and the Investigational Drug Branch, Cancer Therapy Evaluation Program, National Cancer Institute, National Institutes of Health, Rockville (H.S., E.S.) — all in Maryland; the Alliance Statistics and Data Management Center, Mayo Clinic, Rochester, MN (K.V.B., M.O., C.M., G.P.B.); AdventHealth Cancer Institute and the University of Central Florida, Orlando (G.S.); Dana–Farber/Harvard Cancer Center, Boston (S.B., B.M.); UNC Lineberger Comprehensive Cancer Center, Chapel Hill (W.Y.K.), and Duke University Medical Center and Duke Cancer Institute, Durham (J.H., S.H.) — both in North Carolina; the University of Kansas Cancer Center, Westwood (R.P.); Memorial Sloan Kettering Cancer Center, New York (M.Y.T., M.J.M., J.E.R.), and Roswell Park Comprehensive Cancer Center, Buffalo (G.C.) — both in New York; the University of Chicago Comprehensive Cancer Center, Chicago (R.F.S., C.W., Y.W., O.H.), and Loyola University Medical Center, Maywood (M.W.) — both in Illinois; the Alliance Protocol Operations Office, University of Chicago, Chicago (C.W., Y.W., O.H.); Fox Chase Cancer Center, Philadelphia (D.M.G.); Fred Hutchinson Cancer Center and the University of Washington, Seattle (P.G.); Rogel Cancer Center, University of Michigan, Ann Arbor (Z.R.R.); Yale Cancer Center, Yale School of Medicine, New Haven, CT (J.W.K., D.P.); Winship Cancer Institute, Emory University, Atlanta (M.A.B.); Mayo Clinic Comprehensive Cancer Center, Phoenix, AZ (P.S.); Oklahoma University Health Stephenson Cancer Center, Oklahoma City (A. Tripathi); University of Texas Southwestern Medical Center, Dallas (S.C.); Stanford University, Stanford (S.S.), and Kaiser Permanente Riverside Medical Center, Riverside (H.M.) — both in California; and Vanderbilt-Ingram Cancer Center, Nashville (A. Tan).

Source: Apolo, A.B. et al. (2024) ‘Adjuvant pembrolizumab versus observation in muscle-invasive urothelial carcinoma’, New England Journal of Medicine [Preprint]. doi:10.1056/nejmoa2401726.


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